Garlic Mustard
Every spring I observe well-intentioned birders pull Garlic Mustard (Alliaria petiolata) at Pheasant Branch Conservancy, but then leave piles of the invasive plant along the trail. This is a particularly resilient plant and to say that garlic mustard is prolific along the corridor trail is an understatement. If you're going to pull the plants, please bag and remove them from the conservancy – do not simply leave them lying on the ground. Plants that are pulled and left behind will still set seed and by doing so you are unwittingly contributing to the garlic mustard infestation along the stream corridor.
One of the many Garlic Mustard Gardens at Pheasant Branch
When it rains, running water wash the pulled plants (or seeds) off the gravel trail back to the soil. Also, not everybody who walks the trail knows what these piles of plants are and may kick them off the trail. With hundreds of thousands (probably millions) of garlic mustard plants, pulling a few dozen of them isn't going to dent the problem (unless you get the queen plant! j/k). But those who are pulling the plants out by the hundreds should plan on bringing bags and carrying them out of the corridor.
These plants might wash into the stream next rainfall.
Link: Invasive Plants Association of Wisconsin
All images © 2011 Mike McDowell